First round: product aesthetics PK
Laser welding uses a high-energy laser to melt the welded metal to form a joint. In the solar heat-absorbing plate welding, it is welded in the form of a solder joint with a spacing of 3-5 mm. Laser welding does not require pressurization on the workpiece to be welded, the overall deformation is small, and the surface damage to the heat absorbing layer is small, and the ultrasonic metal welding causes wavy deformation of the surface of the sheet due to pressure, although it can be avoided by surface embossing. Deformation, but it will still form a weld mark of about 3mm on the surface of solar heat absorption. Therefore, the appearance of products using laser welding is better than that of ultrasonic metal welding. This round of competition, laser welding is better than ultrasonic metal welding.
Second round: effect persistence PK
The welding spot of laser welding is inferior. When the hot and cold alternates frequently or is subjected to external force, the solder joint is easy to break. Ultrasonic metal welding is to superimpose two objects to be welded by vertical pressure, combined with ultrasonic vibration and pressure to form a solid connection. The bonding time is short and the joint part does not produce casting structure defects, so the welding position is uniform and stable, and the ultrasonic metal There was no fracture after the 90 degree vertical bending test. This round of competition, ultrasonic metal welding is better than laser welding.
Round 3: Thermal Conductivity PK
The use of laser welding will change the physical structure of the welded object, thus affecting its electrical or thermal conductivity, and the laser welding results in a small thermal conduction area between the metal plate and the copper tube of the solar collector, which affects the heat transfer efficiency. Ultrasonic metal welding does not have this problem. Ultrasonic welding can minimize the temperature effect of the material, so that the metal structure does not change, so the electrical conductivity or thermal conductivity after welding is excellent, the electrical resistivity is extremely low or nearly zero, and ultrasonic metal welding has become a conductive and heat conductive material. The best choice, this performance on the flat solar collector can obviously produce the advantages that laser welding can not achieve. According to the test, the ultrasonic metal welding product is about 3% higher than the laser welding conduction efficiency (that is, the water temperature is about 3% under the same working condition). This round of competition, ultrasonic metal welding is significantly better than laser welding.
Round 4: Energy Consumption PK
As a representative product of low-carbon energy-saving and environmental protection, solar water heaters are widely recognized by the society and consumers, and the energy consumption indicators in the production process are also attracting attention. The welding of solar collectors is one of them. From the comparative analysis of the welding principle, it can be known that ultrasonic metal welding can minimize the temperature effect of the material (the temperature of the weld zone does not exceed 50% of the absolute melting temperature of the weld metal), so that the metal structure does not change, so it does not It will anneal metal workpieces without cooling water. In terms of energy consumption, ultrasonic welding can be performed between the same metal and different kinds of metals, which is much less energy-consuming than laser welding. This round of competition, ultrasonic metal welding is better than laser welding.
Round 5: Cost PK
First, the cost of equipment: internationally, the price of ultrasonic welding machine and laser welding machine is equivalent. The procurement cost of single equipment of ultrasonic metal welding machine is lower than that of laser welding machine. The procurement ratio of the two is usually 300,000: 1 million (now domestic laser welding) The price of the machine is also rapidly declining, dropping to about 700,000. The laser welding machine generally has two laser welding heads, and the ultrasonic machine generally has one welding head. For the same production capacity, two ultrasonic welding machines are compared with one laser welding machine.
Second, the cost of use: First, laser welding is suitable for thick materials, such as welding aluminum, the thickness of aluminum plate is generally chosen to be 0.4mm, and ultrasonic welding is suitable for thin products, such as aluminum plate, generally 0.2-0.3mm can be selected. In terms of welding materials, ultrasonic waves are superior. Secondly, the cost of consumables, the consumables for laser welding are xenon lamps and filter cartridges, etc., and the ultrasonic consumables are welding heads. In general, laser welding consumables are cheaper than ultrasonics.